Piston-operated pipettes usually have a calibration function for setting the piston stroke so that the liquid volume dispensed by this stroke equals the indicated volume as precisely as possible. FI patent specification 64752 (corresponding e.g. to EP specification 112887) discloses such a pipette. This pipette comprises a calibration apparatus allowing adjustment of the lower limit of the stroke. In the practice, calibration is performed by weighing the liquid amount dispensed by the pipette with the indicated volume, and by adjusting the lower stopper until the liquid volume equals the indicated one. Calibration is usually performed during the manufacture, before the pipette is taken into use, and is repeated whenever necessary. Pipettes, such as those mentioned above, usually also have a separate volume control function allowing use of the pipette in a given volume range.